Pesticides and Parkinson’s disease: A potential hazard in agricultural communities

Smathorn Thakolwiboon, Parunyou Julayanont, Doungporn Ruthirago

Abstract

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder. Its pathogenesis isrelated to both genetic and environmental factors. Current evidence suggests that pesticideexposure is one of the risk factors of PD. In this review, we summarize four molecularmechanisms of pesticide-induced PD with supportive evidences from both laboratory andepidemiological studies. Rotenone is the first pesticide reported to be associated with PD byinhibiting complex I of mitochondrial electron transport chain. Paraquat, a commonly-usedherbicide in some countries, is an oxidative stressor causing dopaminergic neuronal loss whichcontributes to the pathogenesis of PD. The ubiquitin-proteasome system (UPS) and aldehydedehydrogenase (ALDH) inhibitors cause unwanted proteins (especially alpha-synuclein) and3,4-dihydroxyphenylacetaldehyde (DOPAL) accumulation leading to dopaminergic neuronalapoptosis. In addition, exposure to different pesticides affecting different mechanisms mayhave synergistic effects in increasing risk of PD. Protective glove use, the amount of fat intake,and neuroprotective agents are reported to have disease modification effects for pesticideassociatedPD.